/*abstract class Animal2{
    abstract void shout();
}
class Cat extends Animal2{
    public void shout(){
        System.out.println("喵喵...");
    }
}
class Dog extends Animal2{
    public void shout(){
        System.out.println("汪汪...");
    }
}
public class Exanmple15 {
    public static void main(String[]args){
        Animal2 an1=new Cat();
        Animal2 an2=new Dog();
        an1.shout();
        an2.shout();
    }
}*/
